| 1 | /* |
| 2 | * Syscall wrappers to ensure that nothing gets done in dry_run mode |
| 3 | * and to handle system peculiarities. |
| 4 | * |
| 5 | * Copyright (C) 1998 Andrew Tridgell |
| 6 | * Copyright (C) 2002 Martin Pool |
| 7 | * Copyright (C) 2003-2009 Wayne Davison |
| 8 | * |
| 9 | * This program is free software; you can redistribute it and/or modify |
| 10 | * it under the terms of the GNU General Public License as published by |
| 11 | * the Free Software Foundation; either version 3 of the License, or |
| 12 | * (at your option) any later version. |
| 13 | * |
| 14 | * This program is distributed in the hope that it will be useful, |
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 17 | * GNU General Public License for more details. |
| 18 | * |
| 19 | * You should have received a copy of the GNU General Public License along |
| 20 | * with this program; if not, visit the http://fsf.org website. |
| 21 | */ |
| 22 | |
| 23 | #include "rsync.h" |
| 24 | |
| 25 | #if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H |
| 26 | #include <sys/un.h> |
| 27 | #endif |
| 28 | #ifdef HAVE_SYS_ATTR_H |
| 29 | #include <sys/attr.h> |
| 30 | #endif |
| 31 | |
| 32 | #if defined HAVE_SYS_FALLOCATE && !defined HAVE_FALLOCATE |
| 33 | #include <sys/syscall.h> |
| 34 | #endif |
| 35 | |
| 36 | extern int dry_run; |
| 37 | extern int am_root; |
| 38 | extern int am_sender; |
| 39 | extern int read_only; |
| 40 | extern int list_only; |
| 41 | extern int preserve_perms; |
| 42 | extern int preserve_executability; |
| 43 | |
| 44 | #define RETURN_ERROR_IF(x,e) \ |
| 45 | do { \ |
| 46 | if (x) { \ |
| 47 | errno = (e); \ |
| 48 | return -1; \ |
| 49 | } \ |
| 50 | } while (0) |
| 51 | |
| 52 | #define RETURN_ERROR_IF_RO_OR_LO RETURN_ERROR_IF(read_only || list_only, EROFS) |
| 53 | |
| 54 | int do_unlink(const char *fname) |
| 55 | { |
| 56 | if (dry_run) return 0; |
| 57 | RETURN_ERROR_IF_RO_OR_LO; |
| 58 | return unlink(fname); |
| 59 | } |
| 60 | |
| 61 | #ifdef SUPPORT_LINKS |
| 62 | int do_symlink(const char *lnk, const char *fname) |
| 63 | { |
| 64 | if (dry_run) return 0; |
| 65 | RETURN_ERROR_IF_RO_OR_LO; |
| 66 | |
| 67 | #if defined NO_SYMLINK_XATTRS || defined NO_SYMLINK_USER_XATTRS |
| 68 | /* For --fake-super, we create a normal file with mode 0600 |
| 69 | * and write the lnk into it. */ |
| 70 | if (am_root < 0) { |
| 71 | int ok, len = strlen(lnk); |
| 72 | int fd = open(fname, O_WRONLY|O_CREAT|O_TRUNC, S_IWUSR|S_IRUSR); |
| 73 | if (fd < 0) |
| 74 | return -1; |
| 75 | ok = write(fd, lnk, len) == len; |
| 76 | if (close(fd) < 0) |
| 77 | ok = 0; |
| 78 | return ok ? 0 : -1; |
| 79 | } |
| 80 | #endif |
| 81 | |
| 82 | return symlink(lnk, fname); |
| 83 | } |
| 84 | |
| 85 | #if defined NO_SYMLINK_XATTRS || defined NO_SYMLINK_USER_XATTRS |
| 86 | ssize_t do_readlink(const char *path, char *buf, size_t bufsiz) |
| 87 | { |
| 88 | /* For --fake-super, we read the link from the file. */ |
| 89 | if (am_root < 0) { |
| 90 | int fd = open(path, O_RDONLY|O_NOFOLLOW); |
| 91 | if (fd >= 0) { |
| 92 | int len = read(fd, buf, bufsiz); |
| 93 | close(fd); |
| 94 | return len; |
| 95 | } |
| 96 | if (errno != ELOOP) |
| 97 | return -1; |
| 98 | /* A real symlink needs to be turned into a fake one on the receiving |
| 99 | * side, so tell the generator that the link has no length. */ |
| 100 | if (!am_sender) |
| 101 | return 0; |
| 102 | /* Otherwise fall through and let the sender report the real length. */ |
| 103 | } |
| 104 | |
| 105 | return readlink(path, buf, bufsiz); |
| 106 | } |
| 107 | #endif |
| 108 | #endif |
| 109 | |
| 110 | #ifdef HAVE_LINK |
| 111 | int do_link(const char *fname1, const char *fname2) |
| 112 | { |
| 113 | if (dry_run) return 0; |
| 114 | RETURN_ERROR_IF_RO_OR_LO; |
| 115 | return link(fname1, fname2); |
| 116 | } |
| 117 | #endif |
| 118 | |
| 119 | int do_lchown(const char *path, uid_t owner, gid_t group) |
| 120 | { |
| 121 | if (dry_run) return 0; |
| 122 | RETURN_ERROR_IF_RO_OR_LO; |
| 123 | #ifndef HAVE_LCHOWN |
| 124 | #define lchown chown |
| 125 | #endif |
| 126 | return lchown(path, owner, group); |
| 127 | } |
| 128 | |
| 129 | int do_mknod(const char *pathname, mode_t mode, dev_t dev) |
| 130 | { |
| 131 | if (dry_run) return 0; |
| 132 | RETURN_ERROR_IF_RO_OR_LO; |
| 133 | |
| 134 | /* For --fake-super, we create a normal file with mode 0600. */ |
| 135 | if (am_root < 0) { |
| 136 | int fd = open(pathname, O_WRONLY|O_CREAT|O_TRUNC, S_IWUSR|S_IRUSR); |
| 137 | if (fd < 0 || close(fd) < 0) |
| 138 | return -1; |
| 139 | return 0; |
| 140 | } |
| 141 | |
| 142 | #if !defined MKNOD_CREATES_FIFOS && defined HAVE_MKFIFO |
| 143 | if (S_ISFIFO(mode)) |
| 144 | return mkfifo(pathname, mode); |
| 145 | #endif |
| 146 | #if !defined MKNOD_CREATES_SOCKETS && defined HAVE_SYS_UN_H |
| 147 | if (S_ISSOCK(mode)) { |
| 148 | int sock; |
| 149 | struct sockaddr_un saddr; |
| 150 | #ifdef HAVE_SOCKADDR_UN_LEN |
| 151 | unsigned int len = |
| 152 | #endif |
| 153 | strlcpy(saddr.sun_path, pathname, sizeof saddr.sun_path); |
| 154 | #ifdef HAVE_SOCKADDR_UN_LEN |
| 155 | saddr.sun_len = len >= sizeof saddr.sun_path |
| 156 | ? sizeof saddr.sun_path : len + 1; |
| 157 | #endif |
| 158 | saddr.sun_family = AF_UNIX; |
| 159 | |
| 160 | if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0 |
| 161 | || (unlink(pathname) < 0 && errno != ENOENT) |
| 162 | || (bind(sock, (struct sockaddr*)&saddr, sizeof saddr)) < 0) |
| 163 | return -1; |
| 164 | close(sock); |
| 165 | #ifdef HAVE_CHMOD |
| 166 | return do_chmod(pathname, mode); |
| 167 | #else |
| 168 | return 0; |
| 169 | #endif |
| 170 | } |
| 171 | #endif |
| 172 | #ifdef HAVE_MKNOD |
| 173 | return mknod(pathname, mode, dev); |
| 174 | #else |
| 175 | return -1; |
| 176 | #endif |
| 177 | } |
| 178 | |
| 179 | int do_rmdir(const char *pathname) |
| 180 | { |
| 181 | if (dry_run) return 0; |
| 182 | RETURN_ERROR_IF_RO_OR_LO; |
| 183 | return rmdir(pathname); |
| 184 | } |
| 185 | |
| 186 | int do_open(const char *pathname, int flags, mode_t mode) |
| 187 | { |
| 188 | if (flags != O_RDONLY) { |
| 189 | RETURN_ERROR_IF(dry_run, 0); |
| 190 | RETURN_ERROR_IF_RO_OR_LO; |
| 191 | } |
| 192 | |
| 193 | return open(pathname, flags | O_BINARY, mode); |
| 194 | } |
| 195 | |
| 196 | #ifdef HAVE_CHMOD |
| 197 | int do_chmod(const char *path, mode_t mode) |
| 198 | { |
| 199 | int code; |
| 200 | if (dry_run) return 0; |
| 201 | RETURN_ERROR_IF_RO_OR_LO; |
| 202 | #ifdef HAVE_LCHMOD |
| 203 | code = lchmod(path, mode & CHMOD_BITS); |
| 204 | #else |
| 205 | if (S_ISLNK(mode)) { |
| 206 | # if defined HAVE_SETATTRLIST |
| 207 | struct attrlist attrList; |
| 208 | uint32_t m = mode & CHMOD_BITS; /* manpage is wrong: not mode_t! */ |
| 209 | |
| 210 | memset(&attrList, 0, sizeof attrList); |
| 211 | attrList.bitmapcount = ATTR_BIT_MAP_COUNT; |
| 212 | attrList.commonattr = ATTR_CMN_ACCESSMASK; |
| 213 | code = setattrlist(path, &attrList, &m, sizeof m, FSOPT_NOFOLLOW); |
| 214 | # else |
| 215 | code = 1; |
| 216 | # endif |
| 217 | } else |
| 218 | code = chmod(path, mode & CHMOD_BITS); /* DISCOURAGED FUNCTION */ |
| 219 | #endif /* !HAVE_LCHMOD */ |
| 220 | if (code != 0 && (preserve_perms || preserve_executability)) |
| 221 | return code; |
| 222 | return 0; |
| 223 | } |
| 224 | #endif |
| 225 | |
| 226 | int do_rename(const char *fname1, const char *fname2) |
| 227 | { |
| 228 | if (dry_run) return 0; |
| 229 | RETURN_ERROR_IF_RO_OR_LO; |
| 230 | return rename(fname1, fname2); |
| 231 | } |
| 232 | |
| 233 | #ifdef HAVE_FTRUNCATE |
| 234 | int do_ftruncate(int fd, OFF_T size) |
| 235 | { |
| 236 | int ret; |
| 237 | |
| 238 | if (dry_run) return 0; |
| 239 | RETURN_ERROR_IF_RO_OR_LO; |
| 240 | |
| 241 | do { |
| 242 | ret = ftruncate(fd, size); |
| 243 | } while (ret < 0 && errno == EINTR); |
| 244 | |
| 245 | return ret; |
| 246 | } |
| 247 | #endif |
| 248 | |
| 249 | void trim_trailing_slashes(char *name) |
| 250 | { |
| 251 | int l; |
| 252 | /* Some BSD systems cannot make a directory if the name |
| 253 | * contains a trailing slash. |
| 254 | * <http://www.opensource.apple.com/bugs/X/BSD%20Kernel/2734739.html> */ |
| 255 | |
| 256 | /* Don't change empty string; and also we can't improve on |
| 257 | * "/" */ |
| 258 | |
| 259 | l = strlen(name); |
| 260 | while (l > 1) { |
| 261 | if (name[--l] != '/') |
| 262 | break; |
| 263 | name[l] = '\0'; |
| 264 | } |
| 265 | } |
| 266 | |
| 267 | int do_mkdir(char *fname, mode_t mode) |
| 268 | { |
| 269 | if (dry_run) return 0; |
| 270 | RETURN_ERROR_IF_RO_OR_LO; |
| 271 | trim_trailing_slashes(fname); |
| 272 | return mkdir(fname, mode); |
| 273 | } |
| 274 | |
| 275 | /* like mkstemp but forces permissions */ |
| 276 | int do_mkstemp(char *template, mode_t perms) |
| 277 | { |
| 278 | RETURN_ERROR_IF(dry_run, 0); |
| 279 | RETURN_ERROR_IF(read_only, EROFS); |
| 280 | perms |= S_IWUSR; |
| 281 | |
| 282 | #if defined HAVE_SECURE_MKSTEMP && defined HAVE_FCHMOD && (!defined HAVE_OPEN64 || defined HAVE_MKSTEMP64) |
| 283 | { |
| 284 | int fd = mkstemp(template); |
| 285 | if (fd == -1) |
| 286 | return -1; |
| 287 | if (fchmod(fd, perms) != 0 && preserve_perms) { |
| 288 | int errno_save = errno; |
| 289 | close(fd); |
| 290 | unlink(template); |
| 291 | errno = errno_save; |
| 292 | return -1; |
| 293 | } |
| 294 | #if defined HAVE_SETMODE && O_BINARY |
| 295 | setmode(fd, O_BINARY); |
| 296 | #endif |
| 297 | return fd; |
| 298 | } |
| 299 | #else |
| 300 | if (!mktemp(template)) |
| 301 | return -1; |
| 302 | return do_open(template, O_RDWR|O_EXCL|O_CREAT, perms); |
| 303 | #endif |
| 304 | } |
| 305 | |
| 306 | int do_stat(const char *fname, STRUCT_STAT *st) |
| 307 | { |
| 308 | #ifdef USE_STAT64_FUNCS |
| 309 | return stat64(fname, st); |
| 310 | #else |
| 311 | return stat(fname, st); |
| 312 | #endif |
| 313 | } |
| 314 | |
| 315 | int do_lstat(const char *fname, STRUCT_STAT *st) |
| 316 | { |
| 317 | #ifdef SUPPORT_LINKS |
| 318 | # ifdef USE_STAT64_FUNCS |
| 319 | return lstat64(fname, st); |
| 320 | # else |
| 321 | return lstat(fname, st); |
| 322 | # endif |
| 323 | #else |
| 324 | return do_stat(fname, st); |
| 325 | #endif |
| 326 | } |
| 327 | |
| 328 | int do_fstat(int fd, STRUCT_STAT *st) |
| 329 | { |
| 330 | #ifdef USE_STAT64_FUNCS |
| 331 | return fstat64(fd, st); |
| 332 | #else |
| 333 | return fstat(fd, st); |
| 334 | #endif |
| 335 | } |
| 336 | |
| 337 | OFF_T do_lseek(int fd, OFF_T offset, int whence) |
| 338 | { |
| 339 | #ifdef HAVE_LSEEK64 |
| 340 | #if !SIZEOF_OFF64_T |
| 341 | OFF_T lseek64(); |
| 342 | #else |
| 343 | off64_t lseek64(); |
| 344 | #endif |
| 345 | return lseek64(fd, offset, whence); |
| 346 | #else |
| 347 | return lseek(fd, offset, whence); |
| 348 | #endif |
| 349 | } |
| 350 | |
| 351 | #ifdef HAVE_UTIMENSAT |
| 352 | int do_utimensat(const char *fname, time_t modtime, uint32 mod_nsec) |
| 353 | { |
| 354 | struct timespec t[2]; |
| 355 | |
| 356 | if (dry_run) return 0; |
| 357 | RETURN_ERROR_IF_RO_OR_LO; |
| 358 | |
| 359 | t[0].tv_sec = 0; |
| 360 | t[0].tv_nsec = UTIME_NOW; |
| 361 | t[1].tv_sec = modtime; |
| 362 | t[1].tv_nsec = mod_nsec; |
| 363 | return utimensat(AT_FDCWD, fname, t, AT_SYMLINK_NOFOLLOW); |
| 364 | } |
| 365 | #endif |
| 366 | |
| 367 | #ifdef HAVE_LUTIMES |
| 368 | int do_lutimes(const char *fname, time_t modtime, uint32 mod_nsec) |
| 369 | { |
| 370 | struct timeval t[2]; |
| 371 | |
| 372 | if (dry_run) return 0; |
| 373 | RETURN_ERROR_IF_RO_OR_LO; |
| 374 | |
| 375 | t[0].tv_sec = time(NULL); |
| 376 | t[0].tv_usec = 0; |
| 377 | t[1].tv_sec = modtime; |
| 378 | t[1].tv_usec = mod_nsec / 1000; |
| 379 | return lutimes(fname, t); |
| 380 | } |
| 381 | #endif |
| 382 | |
| 383 | #ifdef HAVE_UTIMES |
| 384 | int do_utimes(const char *fname, time_t modtime, uint32 mod_nsec) |
| 385 | { |
| 386 | struct timeval t[2]; |
| 387 | |
| 388 | if (dry_run) return 0; |
| 389 | RETURN_ERROR_IF_RO_OR_LO; |
| 390 | |
| 391 | t[0].tv_sec = time(NULL); |
| 392 | t[0].tv_usec = 0; |
| 393 | t[1].tv_sec = modtime; |
| 394 | t[1].tv_usec = mod_nsec / 1000; |
| 395 | return utimes(fname, t); |
| 396 | } |
| 397 | |
| 398 | #elif defined HAVE_UTIME |
| 399 | int do_utime(const char *fname, time_t modtime, UNUSED(uint32 mod_nsec)) |
| 400 | { |
| 401 | #ifdef HAVE_STRUCT_UTIMBUF |
| 402 | struct utimbuf tbuf; |
| 403 | #else |
| 404 | time_t t[2]; |
| 405 | #endif |
| 406 | |
| 407 | if (dry_run) return 0; |
| 408 | RETURN_ERROR_IF_RO_OR_LO; |
| 409 | |
| 410 | # ifdef HAVE_STRUCT_UTIMBUF |
| 411 | tbuf.actime = time(NULL); |
| 412 | tbuf.modtime = modtime; |
| 413 | return utime(fname, &tbuf); |
| 414 | # else |
| 415 | t[0] = time(NULL); |
| 416 | t[1] = modtime; |
| 417 | return utime(fname, t); |
| 418 | # endif |
| 419 | } |
| 420 | |
| 421 | #else |
| 422 | #error Need utimes or utime function. |
| 423 | #endif |
| 424 | |
| 425 | #ifdef SUPPORT_PREALLOCATION |
| 426 | int do_fallocate(int fd, OFF_T offset, OFF_T length) |
| 427 | { |
| 428 | #ifdef FALLOC_FL_KEEP_SIZE |
| 429 | #define DO_FALLOC_OPTIONS FALLOC_FL_KEEP_SIZE |
| 430 | #else |
| 431 | #define DO_FALLOC_OPTIONS 0 |
| 432 | #endif |
| 433 | RETURN_ERROR_IF(dry_run, 0); |
| 434 | RETURN_ERROR_IF_RO_OR_LO; |
| 435 | #if defined HAVE_FALLOCATE |
| 436 | return fallocate(fd, DO_FALLOC_OPTIONS, offset, length); |
| 437 | #elif defined HAVE_SYS_FALLOCATE |
| 438 | return syscall(SYS_fallocate, fd, DO_FALLOC_OPTIONS, (loff_t)offset, (loff_t)length); |
| 439 | #elif defined HAVE_EFFICIENT_POSIX_FALLOCATE |
| 440 | return posix_fallocate(fd, offset, length); |
| 441 | #else |
| 442 | #error Coding error in SUPPORT_PREALLOCATION logic. |
| 443 | #endif |
| 444 | } |
| 445 | #endif |